The present invention relates to a slow-acting device to control velocity of a rotary member pivotally supported by a stationary member.
In general, viscous grease has been placed between a rotary shaft connected integrally to a rotary member and a bearing therefor. In this case, shearing resistance of the grease functions as a brake to stifle abrupt rotation.
However, it has been very difficult to achieve an appropriate and uniform clearance between the rotary shaft and the bearing, resulting in failure when applying a great rotary moment, although greater shearing resistance has well been known to accrue from a smaller clearance between shaft and bearing.
The purpose of the present invention is to provide high torque resistance sufficient to provide high rotary energy without the need to be concerned with difficult clearance control.